McGregor's enviable position as a young actor in demand was years in the making. By age 9, buoyed by the success of his uncle Denis Lawson (Local Hero, Star Wars), McGregor decided he would be an actor. He left home at 16 to work with the Perth Repertory Theatre in Scotland, but soon skipped down to London to study acting at the Guildhall School of Music and Drama. McGregor's big break came with the British television series Lipstick on Your Collar, in which he played a clerk with an Elvis obsession. His movie debut followed — a one-liner in Being Human, a Robin Williams fiasco that disappeared from theaters with merciful speed.

In 1994, McGregor teamed up with a trio who changed his young life forever. With director Danny Boyle, producer Andrew MacDonald, and writer John Hodge, McGregor made Shallow Grave, a grisly thriller about three flatmates who dispose of a lodger's body to keep his suitcase full of cash. The film astounded audiences with its rare energy and nihilistic outlook, and was a modest financial success. McGregor won critical raves for his portrayal of the cynical newspaperman on weak moral ground. He then teamed with the trio a second time for Trainspotting, a sensational film based on the novel of the same name by Irvine Welsh. The last line of Mark Renton's opening monologue, "Who needs reasons when you've got heroin?" set the tone for the movie. The response at the box office in Britain was overwhelming: Trainspotting was second only to Four Weddings and a Funeral in total receipts for any British film. Box-office success in America was less resplendent, but McGregor won the hearts of many a critic — and young women.

Those young women were disappointed to learn, however, that the first thing McGregor did after finishing Trainspotting was to marry French production designer Eve Mouvrakis. McGregor describes this stressful time best: "One minute I was lying on the floor with a syringe in my arm, then I got married, then I was standing in this trailer with a wig and a top hat and leather gloves on, and for a moment I thought, 'I can't go from skinhead drug addict to ha-ha-ha curly wig acting.'" But obviously he could. McGregor's role as the pompous love interest of Emma again won him acclaim, and it looked like there would be no end in sight for his string of back-to-back projects. (McGregor and his wife completed their own collaborative effort a year later: Clara McGregor.)

McGregor followed up his role as a horn player in the well-received 1997 social drama Brassed Off with A Life Less Ordinary, a film that perhaps represents the last full collaboration between the actor and Boyle, MacDonald, and Hodge. The four ventured all the way to Utah for the romantic comedy — a hop, skip, and a jump from Hollywood, but still a good distance for McGregor, who says he will never live there. "It would bore me to death — driving around in this Valium lifestyle, you'd soon lose critical faculty." He next starred in Todd Haynes' opulent paean to the rise and fall of the London glam rock scene, Velvet Goldmine, which was produced by Michael Stipe's Single Cell Pictures; and reteamed with Brassed Off director Mark Herman for Little Voice, a film based on Jim Cartwright's hit West End play of the same name. In 1999, McGregor appeared in the role of young Obi-Wan Kenobi in the first of the long-promised prequels to the Star Wars trilogy, Episode I: The Phantom Menace.